Patent GB-490282-A (GB)
Title: A machine for sinking wells, earth boring, mining and so forth
IPC: E21B27/00
Filed: 1936-12-08
Abstract: 490,282. Grab - buckets; boring earth. SOLOMON, G. J. Dec. 8, 1936, No. 33612. [A Specification was laid open to inspection under Sect. 91 of the Acts, Nov. 13, 1937.] [Class 78 (iv)] [Also in Group XXI] In a machine for sinking wells &c. by extraction of earth and provided at its lower end with pivotal jaws for penetrating and grabbing the earth, the jaws are closed by a piston driven by compressed air or other fluid under pressure, and the machine is provided with powerdriven hammer-like or vibratory means actuated separately from the piston to drive the jaws vertically into the ground. The machine comprises a cylinder 1, Fig. 1, having a lower air-tight cover 5 and blocks 11 bolted on, in which jaws 20 are pivoted. These jaws are connected by pin-and-slot connections 22, 23 to the lower end of a piston rod 3 passing through a packing gland 6, and provided with a piston 2. Vibrators 4 are connected to the power by a passage 7 drilled in the cylinder wall and a union 26. In use, the grab is dropped by a cable 32 and power, compressed air, is supplied through the union 26 to actuate the vibrators and drive the jaws 20 into the earth. Then the vibrators are stopped and compressed air admitted through the cable 32, which is hollow, passage 8 in the cylinder wall and port 37 to the space 38 beneath the piston 2. The piston is thereby raised to close the jaws 20. When the machine is raised to the surface, the pressure in space 38 is relieved so that the jaws open and discharge their load. In oozy grounds to increase the capacity of the machine, a cylinder 43, Fig. 4, is inserted between the jaws 49 and the blocks 11. The jaws 49 are so formed as to close completely the bottom of the cylinder 43 when they are closed. In very hard grounds, a second piston slidable on the rod 3 of the piston 2 is used to drive the jaws 20 into the ground. This second piston is actuated by alternately increasing and relieving the pressure-under it. In a modification, the hammer of a winch actuated piston situated above the piston 2 and striking against lugs on the cylinder wall. A modified form of striking piston sliding on the rod of the jaw-closing piston may be used. This striking piston is provided with a portion of smaller diameter at its lower end. In another modification, the striking hammer is raised by an electric motor geared to a rack attached to the hammer, and located in the upper part of the cylinder. When the striking hammer reaches, its upper position, the circuit to the motor is automatically broken and the hammer, falls to drive the jaws into the ground. In a further modification, Fig. 11, the striking piston 90 is operated by the explosion of a gaseous mixture. The fall of the piston compresses air in chamber 95 and draws in. fresh air through a valve 111 to space 89 above the piston. The rebound of the piston closes a cock 104 and draws in a gaseous mixture from a chamber 96 into a chamber 110 in which the pressure is low. The mixture is then exploded by a sparking plug 101 and drives the piston up, compressing the air in 89 and opening a discharge port 105 to the chamber 110. The falling piston opens the cock 104 to discharge the burnt gases which are scavenged by fresh air passing through a valve 91 in the piston from the chamber 89 to the chamber 110. The jaws are closed by pulling the cable 102 to close the port 105 and open a connection between the chamber 89, and a chamber 99 under the jaw closing piston. The Specification as open to inspection under Sect. 91 comprises also a fixed boring kit having three built-up radial blades driven by an internal hammer. A surrounding conical cylinder also constitutes earth penetrating and holding means, there being no pivotal jaws. This subject-matter does not appear in the Specification as accepted.